Dynamically adapting a test workload to accelerate the identification of performance issues

ABSTRACT

An improvement to the process for identifying software problems in performance testing is achieved by dynamically adjusting workloads in real-time to stress the functionality of an application suspected of causing a software problem.

BACKGROUND

The present disclosure generally relates to performance testing, andmore particularly relates to adapting workloads for use in a performancetesting tool.

Performance testing is a complex and time-consuming practice. Everyaspect of the design, code, and execution environment of software isinfluenced by performance. Its pervasive nature makes it a criticaldimension of quality, especially at enterprise levels, as it plays acentral role in software usability. The latest trends in informationtechnology (such as Cloud computing and Service Oriented Architecture)have added to its complexity.

An example of the complexity of performance testing can be readilyappreciated in the context of mail applications such as Gmail™ by GoogleInc. Gmail™ involves over 100 transactions—creating emails, readingemails, deleting emails, creating calendar events, deleting calendarevents, to name a few. Some transactions include no attachments, someinclude small, medium, large, very large attachments. Typically, aperformance engineer models a workload script to emulate expectedbehaviors that would likely occur in a production environment. Theworkload script ideally amplifies the path most frequently traversed (asseen in production runs). For example, folks tend to read more emailsthat they write emails, and they tend to delete some emails and archiveothers and forward a few others. Some replied-to emails will bereply-to-all while others will be simply reply-to-author, and othertransaction possibilities.

Performance test tools monitor the application performance metrics tiedto quality of service objectives, such as average response time, underpeak workload conditions. The performance test software observes thebehavior of complex workloads, such as the volume of transactionsprocessed by an application per second (tps), requests per second, andpage loads per second. Due to the complexity of such workloads, areliable and replicable deployment is not a simple task.

Performance issues can materialize into serious problems, such asoutages in production environments. Assessing these issues isparticularly difficult, especially since the problems are often relatedto the test workloads. These problems are known as workload-dependentperformance bottlenecks (WDPBs). WDPBs are commonly caused byworkload-dependent loops which contain one or more relativelyhigh-consuming operations, such as file Input/Output (I/O) operations,object creation operations, object destruction operations, and userinterface updates.

Techniques exist to identify WDPBs, such as current performance testingtools and performance profiling approaches (e.g., call-tree profiling orstack sampling). However these traditional techniques are inefficientbecause they rely on static workloads. The performance tester mustestimate the size of a workload sufficient to identify performanceissues, and that estimated workload does not change throughout a testrun, which may span several days. Testers often use “standard”workloads, which are adequate for exposing WDPBs in some functions.However, these standard workloads prove insufficient in some cases toidentify WDPBs on small or even relatively large workloads. Moreover, itis often unclear to performance testers how large a workload is largeenough for a workload to expose any possible WDPBs.

Incorrect assumption of workloads brings to light two inefficiencies inthe current performance testing discipline. First, incorrect workloadassumption increases the complexity of performance testing and analysis,indirectly increasing the cost and time required for these activities(commonly limited due to project budget or time constraints). Second,this problem also increases the risk of potentially overlookingperformance issues which might have serious business consequences, suchas unavailability of services or monetary costs.

IBM® Rational Performance Tester® (RPT) is a leading load testing toolin the industry and works as follows. If a tester wants to use RPT forperformance testing of an application (e.g., an IBM Portal®environment), the tester first creates a test script with all thetransactions that are of interest (e.g., login, search, and logout) andthen specifies a workload (e.g. 200 users) which will be used during theentire testing run. The users for tests of this type are commonlyvirtual users. Virtual users simulate system activities of an actualuser. The available workload pool, often subject to licensingthresholds, or system limits, is a delimiting factor.

However, the workload required to identify performance issues might varydependent on the application. The workload of 200 users might beinsufficient if the same tester needs to evaluate the performance of theIBM Lotus Connections® or the IBM WebSphere® (software suites).Different usage scenarios may require different workloads. As anexample, it makes sense to test the commonly-used login/logoutfunctionality with a larger workload than, say a rarely-usedfunctionality.

BRIEF SUMMARY

In one embodiment, a computer-implemented method for dynamicallyadapting a test workload to expose performance issues in a system undertest is disclosed. The system can be a software system including aplurality of applications with associated transactions. Thecomputer-implemented method includes: initializing a diagnosis policy toassess the performance of the system under test, and initializing anadjustment policy for dynamically adjusting a test workload byincreasing the number of uses during a test run to stress thefunctionality of an identified transaction. Parallel to the test run,the computer-implemented method iteratively performs at pre-determinedintervals: collecting monitoring data, producing assessment of systemperformance, identifying possible performance issues, and applying theadjustment policy to increase the number of users in real-time for thetransaction suspected of causing the performance issue, while decreasingthe number of users for those transactions not exhibiting performanceissues.

In a further embodiment, the computer-implemented method the users canbe virtual users. Initializing the adjustment policy includes providingan initial workload, a maximum workload, and a delta workload indicatinghow many additional users to add.

In another embodiment, an information processing system for dynamicallyadapting a test workload to expose performance issues is disclosed. Theinformation processing system includes memory storing instructionsexecuted by a processor device to perform a method including:initializing a diagnosis policy to assess the performance of the systemunder test, and initializing an adjustment policy for dynamicallyadjusting a test workload by increasing the number of uses during a testrun, for an identified transaction. Parallel to the test run, thecomputer-implemented method iteratively performs at pre-determinedintervals: collecting monitoring data, producing assessment of systemperformance, identifying possible performance issues, and applying theadjustment policy to increase the number of users in real-time for thetransaction suspected of causing the performance issues, whiledecreasing the number of users for other transactions not exhibitingperformance issues.

In another embodiment, a computer program product for adaptive workloadadjustment includes a non-transitory storage medium readable by aprocessing circuit and storing instructions for execution by theprocessing circuit for performing a method. The method includes:initializing a diagnosis policy to assess the performance of the systemunder test, and initializing an adjustment policy for dynamicallyadjusting a test workload by increasing the number of uses during a testrun to stress functionality of an identified application. Parallel tothe test run, the computer-implemented method iteratively performs atpre-determined intervals: collecting monitoring data, producingassessment of system performance, identifying possible performanceissues, and applying the adjustment policy to increase the number ofusers in real-time for the transaction suspected of causing theperformance issues, while decreasing the number of users for othertransactions not exhibiting performance issues.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The accompanying figures where like reference numerals refer toidentical or functionally similar elements throughout the separateviews, and which together with the detailed description below areincorporated in and form part of the specification, serve to furtherillustrate various embodiments and to explain various principles andadvantages all in accordance with the present disclosure, in which:

FIG. 1 is a block diagram illustrating one example of an operativeenvironment in which the adaptive workload mechanism is implemented,according to one embodiment of the present disclosure;

FIG. 2 is a simplified illustration of the adaptive workload feedbackloop, according to an embodiment of the disclosure;

FIG. 3 is a simplified schematic of the adaptive workload processrequirements, according to one embodiment of the present disclosure;

FIG. 4 illustrates one example of a diagnosis policy, according to oneembodiment of the present disclosure;

FIG. 5 illustrates one example of an adjustment policy, according to oneembodiment of the present disclosure;

FIG. 6 is an operational flow diagram of the adaptive workload method,according to one embodiment of the present disclosure;

FIG. 7 is an operational flow diagram of the performance evaluationprocess of the adaptive workload method of FIG. 6, according to oneembodiment of the present disclosure;

FIG. 8 illustrates one example of a table combining a diagnosis andevaluation policy, according to one embodiment of the presentdisclosure;

FIG. 9 is a block diagram illustrating a detailed view of an informationprocessing system according to one embodiment of the present disclosure;

FIG. 10 illustrates one example of a cloud computing environmentaccording to one example of the present disclosure; and

FIG. 11 illustrates abstraction model layers according to one example ofthe present disclosure.

DETAILED DESCRIPTION

Typically, workloads are randomized, meaning that the spirit of theworkload intention (e.g. X emails created per hour, Y calendar eventscreated per hour, Z emails deleted per hour, and so forth) is met as perthe performance engineer's outset intention, but there is a littlerandomization in the workload engine to make sure things are not trulydeterministic. This means workload 1 does the same as workload 2, butduring the run things happen in slightly different orders and slightlydifferent ways—this variability is important because if we optimize asystem for a deterministic workload then it will likely fail when thingsdiffer (hence randomization).

In accordance with various aspects of the disclosure, a mechanism,system and method is disclosed for expediting the identification of bugsin performance testing by dynamically adapting a workload for use by aperformance testing tool. Specifically, one or more embodiments disclosea solution to improve the process of identifying software problems inperformance testing by optimizing a randomized workload configurationduring a test run, based on its current, changing, testing environment.The workload is adjusted in real-time, according to reported monitoringdata, in order to stress the functionality (for e.g. login) of anapplication and/or system node suspected of exhibiting a performanceissue (such as a bottleneck) in order to have more certainty aboutwhether or not a problem exists, whether the problem is a bottleneck,memory leak, CPU spike, deadlock, or response time degradation, to namea few.

The workload adjustment is policy-based, executed according to a set ofdiagnostic metrics which are monitored and evaluated in real-time todetermine if any test workload adjustments are required for thetransactions currently under test. Unlike current technologies whichrely on static workloads, the adaptive workload method dynamicallyadapts a workload in real-time for those transactions which aresuspected of suffering a performance issue, thus avoiding the need foradditional test runs. As part of a workload, virtual users areselectively re-tasked during a test run to stress the functionalitysuspected of causing the performance issue. This selective re-taskingprovides the best use of a workload for identifying bottlenecks.

Adaptive, real-time adjustment of a critical resource (workload)maximizes the results obtained by a performance testing tool, avoidingthe need for additional test runs. Improvements in outcomes are realizedboth in the identification of performance issues (bugs), and in theadded certainty regarding the achieved performance goals, as outline ina Service Level Agreement (SLA).

The following is a list of terms and their meanings, as used throughoutthis disclosure:

Glossary

bottleneck—a process in a chain of processes that interferes with thespeedy completion of an application

call-tree profiling—generating a view of a profiled application thatdisplays function execution paths traversed during a run

stack sampling—periodically inspecting the call stacks of all threads.

performance testing—test runs to determine how a system performs under aparticular workload

workload—a quantitative measure of work performed by one user, expressedas number of users

WDPB—workload-dependent performance bottleneck

workload intensity—number of concurrent users within a single run

performance metrics—measures of application performance, such asresponse time

response time—the length of time taken to respond to a request

throughput—maximum number of users served in a given moment

synthetic traffic—use of synthetic (virtual) users to model genuineobserved network traffic

load test—a test of application performance under varying levels ofload, such as with 100 users, with 200 users, and so on

stress test—a test to uncover the breaking point in an application, tobetter expose bottlenecks.

virtual user—a computer-generated user as part of a workload

policy-driven (also rules-based)—decisions made during a test run aremade from a starting point of rules

licensing thresholds—a maximum allowed limit on the number and/or usageof virtual users, generally subject to a fee-based license agreement

service level agreement—an agreement to provide a certain level ofservice to an end user

synthetic load—tasks generated by virtual users

test suite—a collection of test cases

Adaptive Workload Operating Environment

Referring now to FIG. 1, there is shown a simplified illustration of anexemplary operating environment 100 in which the adaptive workloadmethod can be implemented, according to one embodiment. The operatingenvironment 100 includes an adaptive workload system 102 configured toimplement policy-driven adaptive workload monitoring, according to anembodiment of the present disclosure. The adaptive workload system 102can be seamlessly integrated into an existing monitoring infrastructureusing known performance test tools 180 and can run parallel to aperformance test run.

Although depicted as a stand-alone system in operative communicationwith a performance test tool 180, various embodiments support atransparent integration of the adaptive workload system 102 into amonitoring framework. For example, it is to be understood that invarious embodiments the adaptive workload system 102 functions as partof, or a wrapper around, a performance test tool 180. It will be notedthat the adaptive workload system 102 is easily used in tandem withstandard, available performance test tools 180, with little or nomodification to the performance test tools 180 required. Theimplementation of the adaptive workload system 102 features efficiencyand scalability such that it can be deployed on an Internet scale.

The adaptive workload system 102 includes memory 104 with instructionsfor performing an adaptive, policy-driven workload adjustment, accordingto the parameters defined by at least one of: a diagnosis policy 120 andan adjustment policy 125. The adaptive workload processor 150 isoperably coupled with the memory 104 and is configured to execute theinstructions from memory 104 for performing the adaptive workloadmethod, as disclosed. The adaptive workload system 102 further includesstorage 110 configured for storing data as required by the adaptiveworkload processor 150, including operating instructions. Storage 110can be configured to include the diagnosis policy 120, the adjustmentpolicy 125, and the configuration file 130. The policies are configuredprior to a test run and are activated during a test run. Post-testanalysis of the results can produce insights leading to updates to thepolicies.

In one embodiment, a diagnosis policy 120 specifies transactions ofinterest to the tester and provides one or more evaluation parameters(instructions, metrics) to determine if a transaction under test is alikely cause of a performance issue. The transactions of interest can bepulled from the test scripts created by the tester for use by theperformance test tool 180. The diagnosis policy 120 defines performancegoals for any application performance metrics (APMs) 106 that are ofinterest to a tester. The performance goals can be expressed in terms ofbusiness rules tied to a SLA. One can appreciate that the inputs to thediagnosis policy 120 and the adjustment policy 125 are easily generatedfrom the data that is already provided by the tester to the performancetest tool 180.

The diagnosis policy 120 can further provide the data sources requiredto perform the assessment, and any specific input information requiredby the diagnosis policy 120. In one embodiment, the diagnosis policy 120specifies an outside evaluation tool 122 to perform a diagnosis on themonitoring data 105, as noted in the discussion regarding FIG. 7.

The monitoring data 105 refers to the performance test data from themonitored system 190 periodically collected by the adaptive workloadsystem 102. The monitoring data 105 is used to identify transactionsthat may cause a bottleneck, as per the diagnosis policy 120.Performance test tools 180 monitor the APMs 106 tied to quality ofservice objectives, such as average response time, under peak workloadconditions. The performance test software observes the behavior ofcomplex workloads, such as the volume of transactions processed by anapplication per second (tps), requests per second, and page loads persecond. Due to the complexity of such workloads, a reliable andreplicable deployment is not a simple task.

In one embodiment, logging points extract raw data (monitoring data 105)from the application or system on which the application is running. Someexamples of monitoring data are: a) audit data, such as who and when aconfiguration parameter of the system is changed; b) transaction (orrequest) data which measure logical units of work at the applicationlevel; c) performance data, such as CPU and memory utilization; d)analytical data, such as page load times for a Web server; and e) eventdata, such as logging a call to a login service and its return code ofsuccess or failure.

For purposes of this disclosure, a system node is any addressablecomponent or process that forms a part of a system under test. A systemnode can include a server, such as a Web server; a directory such as anLDAP directory; a database; an application; a device such as a printer;and/or a process, to name a few. In a distributed system it isespecially advantageous to set multiple logging points across nodesbecause a failure in one node can cause a performance-degradingcondition in another node.

An adjustment policy 125 provides the rules, or guidelines, foradjusting (either increasing or decreasing) the workload for a specifictransaction or functionality identified by the adaptive workload system102 as suspicious (likely to negatively affect performance). Anadjustment policy 125 might require any upper and lower workload limitsin order to know the workload range within which the adjustment policy125 might adjust the workload of the tested transactions.

The configuration file 130 can include the configuration specificationsfor initiating and maintaining the adaptive workload process, asdisclosed. For example, the configuration file 130 can include acollection policy specifying the amount of monitoring data 105 tocollect and how often. Some examples of configuration parameters are: 1)the sample interval in order to know how frequently the diagnosis policy120 will be evaluated, 2) indicate which diagnosis and adjustmentpolicies will be used (among the available alternatives), 3) provide theparticular inputs required by the chosen policies.

For example, a diagnosis policy 120 might be based on APMs 106 (e.g.response time or throughput) and have as evaluation criterion that anyincrease above a given response time threshold (over a response timebaseline) is considered an abnormal behavior. In this scenario, thetester would need to provide the response time baselines and theirrespective response time thresholds for the transactions under test.Although only one of each policy is depicted, it will be apparent thatvarious policies specifying different diagnosis and adjustmentscenarios, and configurations, can be provided.

The policies guide the performance of the adaptive workload processor150 in adjusting the workload used by a performance test tool 180 on amonitored system 190 to best identify WDPBs.

The interval timer 155 is operably coupled with the adaptive workloadprocessor 150 and can be embodied as a system clock or global clock. Theinterval timer 155 is implemented by the adaptive workload processor 150to schedule test performance data collections at pre-set intervals, asper the stored parameters in the configuration file 130. Once themonitoring data 105 is collected at pre-specified time intervals, theadaptive workload processor 150 analyzes the monitoring data 105 byinvoking the diagnosis policy 120 to assess application performance. Forexample, monitoring data 105 for transactions is collected and analyzedto derive APMs 106 such as average response time and throughput.

Adaptive Workload Feedback Loop—FIG. 2

FIG. 2 shows an adaptive workload feedback loop 200, according to oneembodiment. An adaptive workload processor 150 is configured toimplement a dynamic workload adjustment method, automatically adjustingthe workload 140 used by a performance testing tool 180 on a monitoredsystem 190, based on the system's 190 observed behaviors. The adaptiveworkload processor 150 implements the adaptive workload method within arunning test environment, subject to configuration parameters set out ina diagnosis policy 120 and an adjustment policy 125.

The adaptive workload method can run parallel to the performance testtool 180, leveraging leverages the utility of an existing performancetest tool 180 to collect monitoring data 105 from the monitored system190. The monitoring data 105 is periodically evaluated by the adaptiveworkload processor 150 to determine if any workload adjustment isrequired, as per the diagnosis policy 120. If an adjustment is deemednecessary, the adaptive workload processor 150 performs the necessaryadjustments to the workload 140 in real-time, according to theadjustment policy 125. The workload adjustment is provided to theperformance testing tool 180 which continues its evaluation of themonitored system 190, with an adjusted workload 145.

In accord with various aspects of this disclosure, a workload 140 isincreased with the intent of increasing the number oftransactions/events to stress a functionality identified as suspicious.We refer to a workload 140 as the number of users; however, one withknowledge in the art will appreciate that a workload 140 represents anumber of transactions/events occurring in a system that can beattributable to a user (actual user or virtual user). Therefore,increasing a workload 140 by means other than increasing a number ofusers is within the spirit and scope of the disclosure.

Assume a tester wishes to gain a better insight into the loginfunctionality and whether or not its performance fulfills the SLA interms of response time and throughput. Assume licensing thresholdsrestrict the number of virtual users to 600. In order to optimize theresults from a performance testing run, the tester adjusts the initialworkload 140 to decrease the number of users for the logout and searchfunctionalities to 50 users each because these transactions are outsideof the tester's area of interest. The tester increases the workload 140for the login transactions to 500 users in order to make better use ofthose resources by stressing the login functionality.

Adaptive Workload Process Overview—FIG. 3

FIG. 3 shows a simplified, basic process overview 300 of the adaptiveworkload method, according to one embodiment. At a minimum, the inputsto the process are: at least one diagnosis policy 120, at least oneadjustment policy 125, a configuration file 130, and an initial workload140. The diagnosis policy 120, adjustment policy 125, and configurationfile 130 are depicted as separate blocks for clarity of presentation inorder to underscore their use in the adaptive workload method. It is tobe understood that the blocks are not to be construed as separatephysical, or logical, components. The configuration file 130, forexample, can contain the diagnosis policy 120 and the adjustment policy125.

During the input phase 310 of the process, the tester provides thepolicies that are applicable to the tester's areas of interest. In oneexample, the tester submits the policies, perhaps as scripts, prior tothe test execution. The configuration parameters are provided, framingthe test requirements. An initial workload 140 must be specified priorto the test run 320. In one embodiment, the initial workload 140 is setby the performance test tool 180. In another embodiment, the initialworkload 140 is specified in the configuration file 130.

During the test phase 320, the adaptive workload processor 150 evaluatesmonitoring data 105 from the monitored system 190 and makes anynecessary changes to the workload 140. The adjusted workload 145 isprovided to the performance testing tool 180 which continues to operateon the monitored system 190, providing monitoring data 105 evaluated bythe adaptive workload processor 150. The results of the adaptiveworkload method are the improved identification of bugs 399, such asWDPBs.

Policy Examples—FIGS. 4 and 5

Different policies can be associated with different performance testtools 180, with different capabilities, parameters, and configurationoptions. Non-limiting examples of possible policies which can beapplicable to a performance testing tool 180 (such as the IBM® RPT toolpreviously discussed) are:

Performance metric diagnosis policy, as shown in the table 400 of FIG.4. This policy is based on a set of APMs 106 (such as response time andthroughput). Whenever the performance of any transaction exceeds adefined threshold (above an expected baseline), that transaction isconsidered suspicious, i.e., a likely candidate to suffer a performanceissue.

FIG. 4 represents a non-limiting example of a diagnosis policy 120,according to one embodiment. The diagnosis policy 120 of FIG. 4 ispresented as a table 400 for clarity of understanding. It will beappreciated that the diagnosis policy 120 can be expressed as a command,or script, or as a look-up table as shown in FIG. 4. Table 400 featuresperformance parameters 410 of APM 106, baseline, tolerance threshold,and performance goal. For example, the baseline for the APM 106 ofResponse Time is set at 1800 ms. This figure can be derived from pasttest and/or production runs. According to the example of FIG. 4, thethreshold tolerance for the response time metric is an additional 1000ms, for a performance goal requiring a maximum response time of 1900 ms.A designated application with a response time over 1900 ms is to beidentified as a suspect. In this case, the adaptive workload processor150 triggers an increase in the workload 140 for the suspectapplication.

FIG. 5 shows a non-limiting example of an adjustment policy 125 for thelogin, search, and logout functions 510, according to one embodiment.The adjustment policy 125 of FIG. 5 is presented as a table 500 forclarity of understanding. Table 500 features adjustment parameters fordirecting the adjustment of a workload 140 on a test system 190. As anexample, FIG. 5 provides the types of transactions 510 that are ofinterest to a user, such as login, search, and logout. It will beappreciated that these examples are not comprehensive, and many moretypes of transactional data can be evaluated within the spirit and scopeof the disclosure.

In one embodiment, a tester provides inputs such as: the initialworkload 140 to be used (e.g. 200 users); the delta workload, whichindicates how much the workload should change whenever an adjustment isrequired (e.g. 10 users). The delta workload can be provided as anexplicit amount (10 users), or as a percentage amount (5%). Anadditional parameter provided by a tester can be the maximum possibleworkload 580 that the performance test can use (e.g. 2,000 users), aparameter which would likely depend on the characteristics of themachine where the test loader is executed, as well as licensing limits.

Whenever the adjustment policy 125 is executed, it will increase theworkload 140 of those transactions which are suspicious of suffering aperformance issue, by increasing the workload 140 by the defined delta,yet without exceeding the maximum allowed workload 580. At the sametime, the workloads 140 of the well-behaved transactions (those whichare not suspected of suffering a performance issue) are decreased inorder to stress the suspicious transactions as much as possible, withinthe maximum allowed workload 580.

For each type of transaction, table 500 provides the adjustmentparameters 540 for an initial workload, a delta workload, and a maximumworkload, per transaction 510. Once a transaction 510 is identified bythe diagnosis policy 120 as failing to meet a performance goal, theadjustment policy 125 is queried to determine the adjustment parameters540 for that particular transaction. For example, assume the adaptiveworkload processor 150 determines that the email reply functionalitymight be causing a bottleneck, or other performance issue. In that case,the adjustment policy 125 mandates an increase of 200 users to theworkload 140, up to a maximum of 1500 users for that functionality. Itwill be noted that the total of the maximum workload for each of thetransactions listed in the example of FIG. 5 adds up to 4,500, more thanthe total workload maximum 580 of 2,000 users. This is because anyworkload increase to one transaction will incur a decrease in othertransaction.

Supplementary Tool Diagnosis Policy (STDP): This type of policy makesuse of supplementary sources 122 (outside the direct control of aperformance testing tool 180) to identify suspicious transactions. Oneexample is discussed in the narrative regarding FIG. 7. The STDP mustprovide the source 122. In one embodiment, the source 122 can beprovided in the form of a web address.

It is anticipated that the adaptive workload system 102 will increaseits utility over time with continual propagation and calibration of thediagnosis and adjustment policies.

Operational Flow Diagram—FIG. 6

FIG. 6 shows an operational flow diagram 600 of the process fordynamically adapting a workload for a performance testing tool 180,according to an embodiment. The process for dynamically adapting a testworkload 140 can run parallel to the performance test run. Theoperational flow begins prior to the test run, at step 610, byinitializing a configuration file 130, as well as at least one each oftwo different types of policies—a diagnosis policy 120 and an adjustmentpolicy 125.

Once the initialization of the process is complete, the workloadadjustment process can run in a loop parallel to the performance testexecution. As part of the configuration file 130, a sampling intervaltime is decided upon so that the application under test has some time toprocess a certain amount of transactions (as per the current workloadconditions) before any diagnosis is attempted. In step 615 the workloadadjustment process waits the configured wait time, as set forth in theconfiguration file 130. After waiting the configured sampling intervaltime in step 615, a set of monitoring data 105 samples is collected(following the data sources defined by the diagnosis policy 120) in step620.

After the collection of step 620 is complete, the collected monitoringdata 105 is evaluated following the evaluation criteria defined in theselected diagnosis policy 120 in step 630. As part of the evaluation,the adaptive workload processor 150 applies metrics to the monitoringdata 105 to derive APMs 106, such as average response time, throughput,and the like.

Transactions or functionality not meeting their performance goals, asstated in the diagnosis policy 120, are considered to exhibitperformance issues. If the evaluation in step 630 reports a transactionlikely to cause a performance issue, as determined in decision step 640,the suspect transaction(s) is(are) identified in step 650 as likelycandidates for causing a WDPB.

Once identified, the applicable adjustment policy 125 is referenced tolocate the identified transaction and its associated workload adjustmentparameters 540. In step 660 the workload 140 of any suspect transactionsis adjusted to an adjusted workload 145, as per the workload adjustmentparameters 540 of the matched transaction. The workload adjustment iscontrolled by the workload adjustment parameters 640 of the selectedadjustment policy 125.

For example, assume the evaluation in step 630 uncovered that one logintransaction (or a pre-defined threshold of login transactions) wasexperiencing response times greater than 1900 ms, and that this“suspect” transaction was specified as a transaction of interest in thediagnosis policy 120. The applicable adjustment policy 125 is referencedto determine what action to take by matching the “suspect” transactionwith its counterpart in the adjustment policy 125. According to theparameters 540 set forth in the adjustment policy 125, the adaptiveworkload processor 150 increases the number of users for the loginfunctionality of the matched “suspect” transaction by the specifieddelta of 50 users.

In step 670 the APMs 106 and are stored for future analysis to enablefuture updates to the diagnosis policy 120 and the adjustment policy 125with the insight “learned” from the test runs. In step 680 if the testrun continues, then the workload adjustment process loops back to step615. The process iteratively continues until the performance testterminates.

In summary, by implementing the above inventive steps, the workloadadjustment method will be able to dynamically adapt the workload 140used in a performance testing tool 180 in order to maximize the resultsof performance testing over a tested system 190.

Operational Flow for Performance Evaluation—FIG. 7

FIG. 7 shows an operational flow diagram 700 of the performanceevaluation process 630 from FIG. 6, according to one embodiment, whereina supplementary evaluation tool 122 outside the direct control of theperformance testing tool 180 is employed. Many evaluation tools 122 areavailable and easy to use in the identification of suspicioustransactions. As a non-limiting example, the IBM® Whole-System Analysisof Idle Time tool (WAIT®) can be advantageously used with the adaptiveworkload method as discussed above. This publicly available tool is alightweight expert system that helps to identify the main performanceinhibitors in Java® systems.

Referring to FIG. 7, the process begins at step 732 by accessing theoutside evaluation tool 122. In the case of IBM's WAIT® tool, this canbe as simple as entering a web address to serve a web page. In step 734the diagnosis policy 120 provides the data to be evaluated, such as byuploading it to the website (wait.ibm.com) directly from the web page.The diagnosis policy 120 may provide all of the collected monitoringdata 105, or only a portion of the collected monitoring data 105, to thesupplementary diagnostic tool 122. The amount to provide may be limitedby the tool's 122 usage requirements.

In step 736 the diagnosis policy 120 receives the evaluation resultsfrom the supplementary diagnostic tool 122. The results can be in theform of a report with the findings ranked by frequency and impact. Inoptional step 738, the diagnosis policy 120 is configured to filter thereport so that only the most egregious problems receive the attention ofthe adjustment policy 125. This process can be repeated multiple timesto monitor a system 190 through time. A diagnosis policy 120 mightexploit the outputs of a supplementary resource 122 such as WAIT® toidentify the transactions which are involved in the functionality whichis experiencing bottlenecks (e.g. CPU, I/O latency, or deadlock). Then,those transactions can be marked as suspicious, invoking the adjustmentpolicy 125.

Combination Diagnosis and Adjustment Policy—FIG. 8

In one embodiment, the diagnosis policy 120 and the adjustment policy125 are combined into one script, file, or table. FIG. 8 shows anon-limiting example of a look-up table 800 combining both the diagnosisand adjustment policies. Table 800 stores various transactions/functions802 that may be of interest to a tester in diagnosing performanceissues. Associated with each transaction/function 802 are multipleapplicable APMs 106, such as response time and throughput. For each APM106, the table 800 states a performance goal 810 which can be formulatedas a business rule tied to a SLA. For example, assume the SLA mandates amaximum login response time of 1900 ms. This information is included intable 800 as the performance goal 810 for login response time (maximum1900 ms). A recorded login response time (or an average login responsetime) over 1900 ms triggers an associated workload adjustment action820. Referencing table 800, in this example the adaptive workloadprocessor 150 triggers an increase to the workload 140 by 150 users, upto a maximum of 750 users.

Information Processing System Example—FIG. 9

FIG. 9 illustrates one example of an information processing system 902that can be utilized in various embodiments of the present disclosure.The information processing system 902 shown in FIG. 9 is only oneexample of a suitable system and is not intended to limit the scope ofuse or functionality of embodiments of the present disclosure describedabove. The information processing system 902 of FIG. 9 is capable ofimplementing and/or performing any of the functionality set forth above.Any suitably configured processing system can be used as the informationprocessing system 902 in embodiments of the present disclosure.

The information processing system 902 is operational with numerous othergeneral purpose or special purpose computing system environments orconfigurations. Examples of well-known computing systems, environments,and/or configurations that may be suitable for use with the informationprocessing system 902 include, yet limited to, personal computersystems, server computer systems, thin clients, thick clients, hand-heldor laptop devices, multiprocessor systems, microprocessor-based systems,set top boxes, programmable consumer electronics, network PCs,minicomputer systems, mainframe computer systems, and distributed cloudcomputing environments that include any of the above systems or devices,and the like.

The information processing system 902 may be described in the generalcontext of computer system-executable instructions, such as programmodules, being executed by a computer system. Generally, program modulesmay include routines, programs, objects, components, logic, datastructures, and so on that perform particular tasks or implementparticular abstract data types. The information processing system 902may be practiced in various computing environments such as conventionaland distributed cloud computing environments where tasks are performedby remote processing devices that are linked through a communicationsnetwork. In a distributed cloud computing environment, program modulesmay be located in both local and remote computer system storage mediaincluding memory storage devices.

As illustrated in FIG. 9, the information processing system 902 is inthe form of a general-purpose computing device. The components of theinformation processing system 902 can include, although are not limitedto, one or more processors or processing units 904, a system memory 906,and a bus 908 that couples various system components including thesystem memory 906 to the processor 904.

The bus 908 represents one or more of any of several types of busstructures, including a memory bus or memory controller, a peripheralbus, an accelerated graphics port, and a processor or local bus usingany of a variety of bus architectures. By way of example, and notlimitation, such architectures include Industry Standard Architecture(ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA)bus, Video Electronics Standards Association (VESA) local bus, andPeripheral Component Interconnects (PCI) bus.

The system memory 906, in one embodiment, includes the adaptive workloadprocessor 150 and its components discussed above. Even though FIG. 9shows the adaptive workload processor 150 residing in the main memory,the adaptive workload processor 150 or at least one of its componentscan reside within the processor 904, be a separate hardware component,and/or be distributed across a plurality of information processingsystems and/or processors.

The system memory 906 can also include computer system readable media inthe form of volatile memory, such as random access memory (RAM) 910and/or cache memory 912. The information processing system 902 canfurther include other removable/non-removable, volatile/non-volatilecomputer system storage media. By way of example only, a storage system914 can be provided for reading from and writing to a non-removable orremovable, non-volatile media such as one or more solid state disksand/or magnetic media (typically called a “hard drive”). A magnetic diskdrive for reading from and writing to a removable, non-volatile magneticdisk (e.g., a “floppy disk”), and an optical disk drive for reading fromor writing to a removable, non-volatile optical disk such as a CD-ROM,DVD-ROM or other optical media can be provided. In such instances, eachcan be connected to the bus 908 by one or more data media interfaces.The memory 906 can include at least one program product having a set ofprogram modules that are configured to carry out the functions of anembodiment of the present disclosure.

Program/utility 916, having a set of program modules 918, may be storedin memory 906 by way of example, and not limitation, as well as anoperating system, one or more application programs, other programmodules, and program data. Each of the operating system, one or moreapplication programs, other program modules, and program data or somecombination thereof, may include an implementation of a networkingenvironment. Program modules 918 generally carry out the functionsand/or methodologies of embodiments of the present disclosure.

The information processing system 902 can also communicate with one ormore external devices 920 such as a keyboard, a pointing device, adisplay 922, etc.; one or more devices that enable a user to interactwith the information processing system 902; and/or any devices (e.g.,network card, modem, etc.) that enable computer system/server 902 tocommunicate with one or more other computing devices. Such communicationcan occur via I/O interfaces 924. The information processing system 902can communicate with one or more networks such as a local area network(LAN), a general wide area network (WAN), and/or a public network (e.g.,the Internet) via network adapter 926. As depicted, the network adapter926 communicates with the other components of information processingsystem 902 via the bus 908. Other hardware and/or software componentscan also be used in conjunction with the information processing system902. Examples include, yet are not limited to: microcode, devicedrivers, redundant processing units, external disk drive arrays, RAIDsystems, tape drives, and data archival storage systems.

Cloud Computing Environment—FIG. 10

It is understood in advance that although the following is a detaileddiscussion on cloud computing, implementation of the teachings recitedherein are not limited to a cloud computing environment. Rather, variousembodiments of the present disclosure are capable of being implementedin conjunction with any other type of computing environment now known orlater developed. For example, various embodiments of the presentdisclosure are applicable to any computing environment with avirtualized infrastructure or any other type of computing environment.

For convenience, the Detailed Description includes the followingdefinitions which have been derived from the “Draft NIST WorkingDefinition of Cloud Computing” by Peter Mell and Tim Grance, dated Oct.7, 2009, which is cited in an IDS filed herewith, and a copy of which isattached thereto. However, it should be noted that cloud computingenvironments that are applicable to one or more embodiments of thepresent disclosure are not required to correspond to the followingdefinitions and characteristics given below or in the “Draft NISTWorking Definition of Cloud Computing” publication. It should also benoted that the following definitions, characteristics, and discussionsof cloud computing are given as non-limiting examples.

Cloud computing is a model of service delivery for enabling convenient,on-demand network access to a shared pool of configurable computingresources (e.g. networks, network bandwidth, servers, processing,memory, storage, applications, virtual machines, and services) that canbe rapidly provisioned and released with minimal management effort orinteraction with a provider of the service. This cloud model may includeat least five characteristics, at least three service models, and atleast four deployment models.

Characteristics are as follows:

On-demand self-service: a cloud consumer can unilaterally provisioncomputing capabilities, such as server time and network storage, asneeded automatically without requiring human interaction with theservice's provider.

Broad network access: capabilities are available over a network andaccessed through standard mechanisms that promote use by heterogeneousthin or thick client platforms (e.g., mobile phones, laptops, and PDAs).

Resource pooling: the provider's computing resources are pooled to servemultiple consumers using a multi-tenant model, with different physicaland virtual resources dynamically assigned and reassigned according todemand. There is a sense of location independence in that the consumergenerally has no control or knowledge over the exact location of theprovided resources; however, may be able to specify location at a higherlevel of abstraction (e.g., country, state, or datacenter).

Rapid elasticity: capabilities can be rapidly and elasticallyprovisioned, in some cases automatically, to quickly scale out andrapidly released to quickly scale in. To the consumer, the capabilitiesavailable for provisioning often appear to be unlimited and can bepurchased in any quantity at any time.

Measured service: cloud systems automatically control and optimizeresource use by leveraging a metering capability at some level ofabstraction appropriate to the type of service (e.g., storage,processing, bandwidth, and active user accounts). Resource usage can bemonitored, controlled, and reported providing transparency for both theprovider and consumer of the utilized service.

Service Models are as follows:

Software as a Service (SaaS): the capability provided to the consumer isto use the provider's applications running on a cloud infrastructure.The applications are accessible from various client devices through athin client interface such as a web browser (e.g., web-based email). Theconsumer does not manage or control the underlying cloud infrastructureincluding network, servers, operating systems, storage, or evenindividual application capabilities, with the possible exception oflimited user-specific application configuration settings.

Platform as a Service (PaaS): the capability provided to the consumer isto deploy onto the cloud infrastructure consumer-created or acquiredapplications created using programming languages and tools supported bythe provider. The consumer does not manage or control the underlyingcloud infrastructure including networks, servers, operating systems, orstorage, yet has control over the deployed applications and possiblyapplication hosting environment configurations.

Infrastructure as a Service (IaaS): the capability provided to theconsumer is to provision processing, storage, networks, and otherfundamental computing resources where the consumer is able to deploy andrun arbitrary software, which can include operating systems andapplications. The consumer does not manage or control the underlyingcloud infrastructure yet has control over operating systems, storage,deployed applications, and possibly limited control of select networkingcomponents (e.g., host firewalls).

Deployment Models are as follows:

Private cloud: the cloud infrastructure is operated solely for anorganization. It may be managed by the organization or a third party andmay exist on-premises or off-premises.

Community cloud: the cloud infrastructure is shared by severalorganizations and supports a specific community that has shared concerns(e.g., mission, security requirements, policy, and complianceconsiderations). It may be managed by the organizations or by a thirdparty, and may exist on-premises or off-premises.

Public cloud: the cloud infrastructure is made available to the generalpublic or a large industry group and is owned by an organization sellingcloud services.

Hybrid cloud: the cloud infrastructure is a composition of two or moreclouds (private, community, or public) that remain unique entities yetare bound together by standardized or proprietary technology thatenables data and application portability (e.g., cloud bursting forload-balancing between clouds).

A cloud computing environment is service oriented with a focus onstatelessness, low coupling, modularity, and semantic interoperability.At the heart of cloud computing is an infrastructure comprising anetwork of interconnected nodes.

Referring now to FIG. 10, illustrative cloud computing environment 1002is depicted. As shown, cloud computing environment 1002 includes one ormore information processing systems 902 with which local computingdevices used by cloud consumers, such as, for example, personal digitalassistant (PDA) or cellular telephone 1004, desktop computer 1006,laptop computer 1008, and/or automobile computer system 1010 maycommunicate. Each node within the environment 1002 may communicate withone another. They may be grouped (not shown) physically or virtually, inone or more networks, such as Private, Community, Public, or Hybridclouds as described hereinabove, or a combination thereof. This allowscloud computing environment 1002 to offer infrastructure, platformsand/or software as services for which a cloud consumer does not need tomaintain resources on a local computing device. It is understood thatthe types of computing devices 1004, 1006, 1008, 1010 shown in FIG. 10are intended to be illustrative only and that computing nodes 902 andcloud computing environment 1002 can communicate with any type ofcomputerized device over any type of network and/or network addressableconnection (e.g., using a web browser).

Referring now to FIG. 11, a set of functional abstraction layersprovided by cloud computing environment 1002 (FIG. 10) is shown. Itshould be understood in advance that the components, layers, andfunctions shown in FIG. 11 are intended to be illustrative only andembodiments of the disclosure are not limited thereto. As depicted, thefollowing layers and corresponding functions are provided:

Hardware and software layer 1102 includes hardware and softwarecomponents. Examples of hardware components include mainframes, in oneexample IBM® zSeries® systems; RISC (Reduced Instruction Set Computer)architecture based servers, in one example IBM pSeries® systems; IBMxSeries® systems; IBM BladeCenter® systems; storage devices; networksand networking components. Examples of software components includenetwork application server software, in one example IBM WebSphere®application server software; and database software, in one example IBMDB2® database software. (IBM, zSeries, pSeries, xSeries, BladeCenter,WebSphere, and DB2 are trademarks of International Business MachinesCorporation registered in many jurisdictions worldwide)

Virtualization layer 1104 provides an abstraction layer from which thefollowing examples of virtual entities may be provided: virtual servers;virtual storage; virtual networks, including virtual private networks;virtual applications and operating systems; and virtual clients.

In one example, management layer 1106 may provide the functionsdescribed below. Resource provisioning provides dynamic procurement ofcomputing resources and other resources that are utilized to performtasks within the cloud computing environment. Metering and Pricingprovide cost tracking as resources are utilized within the cloudcomputing environment, and billing or invoicing for consumption of theseresources. In one example, these resources may comprise applicationsoftware licenses. Security provides identity verification for cloudconsumers and tasks, as well as protection for data and other resources.User portal provides access to the cloud computing environment forconsumers and system administrators. Service level management providescloud computing resource allocation and management such that requiredservice levels are met. Service Level Agreement (SLA) planning andfulfillment provide pre-arrangement for, and procurement of, cloudcomputing resources for which a future requirement is anticipated inaccordance with an SLA.

Workloads layer 1108 provides examples of functionality for which thecloud computing environment may be utilized. Examples of workloads andfunctions which may be provided from this layer include: mapping andnavigation; software development and lifecycle management; virtualclassroom education delivery; data analytics processing; transactionprocessing; and workload processing.

Non-Limiting Examples

As will be appreciated by one skilled in the art, aspects of the presentdisclosure may be embodied as a system, method, or computer programproduct. Accordingly, aspects of the present disclosure may take theform of an entirely hardware embodiment, an entirely software embodiment(including firmware, resident software, micro-code, etc.) or anembodiment combining software and hardware aspects that may allgenerally be referred to herein as a “circuit,” “module” or “system.”Furthermore, aspects of the present disclosure may take the form of acomputer program product embodied in one or more computer readablemedium(s) having computer readable program code embodied thereon.

Any combination of one or more computer readable medium(s) may beutilized. The computer readable medium may be a computer readable signalmedium or a computer readable storage medium. A computer readablestorage medium may be, for example, although not limited to, anelectronic, magnetic, optical, electromagnetic, infrared, orsemiconductor system, apparatus, or device, or any suitable combinationof the foregoing. More specific examples (a non-exhaustive list) of thecomputer readable storage medium would include the following: anelectrical connection having one or more wires, a portable computerdiskette, a hard disk, a random access memory (RAM), a read-only memory(ROM), an erasable programmable read-only memory (EPROM or Flashmemory), an optical fiber, a portable compact disc read-only memory(CD-ROM), an optical storage device, a magnetic storage device, or anysuitable combination of the foregoing. In the context of this document,a computer readable storage medium may be any tangible medium that cancontain, or store a program for use by or in connection with aninstruction execution system, apparatus, or device.

A computer readable signal medium may include a propagated data signalwith computer readable program code embodied therein, for example, inbaseband or as part of a carrier wave. Such a propagated signal may takeany of a variety of forms, including, although not limited to,electro-magnetic, optical, or any suitable combination thereof. Acomputer readable signal medium may be any computer readable medium thatis not a computer readable storage medium and that can communicate,propagate, or transport a program for use by or in connection with aninstruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmittedusing any appropriate medium, including although not limited to,wireless, wireline, optical fiber cable, RF, etc., or any suitablecombination of the foregoing.

Computer program code for carrying out operations for aspects of thepresent disclosure may be written in any combination of one or moreprogramming languages, including an object oriented programming languagesuch as Java, Smalltalk, C++ or the like and conventional proceduralprogramming languages, such as the “C” programming language or similarprogramming languages. The program code may execute entirely on theuser's computer, partly on the user's computer, as a stand-alonesoftware package, partly on the user's computer and partly on a remotecomputer or entirely on the remote computer or server. In the latterscenario, the remote computer may be connected to the user's computerthrough any type of network, including a local area network (LAN) or awide area network (WAN), or the connection may be made to an externalcomputer (for example, through the Internet using an Internet ServiceProvider).

Aspects of the present disclosure have been discussed above withreference to flowchart illustrations and/or block diagrams of methods,apparatus (systems) and computer program products according to variousembodiments of the disclosure. It will be understood that each block ofthe flowchart illustrations and/or block diagrams, and combinations ofblocks in the flowchart illustrations and/or block diagrams, can beimplemented by computer program instructions. These computer programinstructions may be provided to a processor of a general purposecomputer, special purpose computer, or other programmable dataprocessing apparatus to produce a machine, such that the instructions,which execute via the processor of the computer or other programmabledata processing apparatus, create means for implementing thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

These computer program instructions may also be stored in a computerreadable medium that can direct a computer, other programmable dataprocessing apparatus, or other devices to function in a particularmanner, such that the instructions stored in the computer readablemedium produce an article of manufacture including instructions whichimplement the function/act specified in the flowchart and/or blockdiagram block or blocks.

The computer program instructions may also be loaded onto a computer,other programmable data processing apparatus, or other devices to causea series of operational steps to be performed on the computer, otherprogrammable apparatus or other devices to produce a computerimplemented process such that the instructions which execute on thecomputer or other programmable apparatus provide processes forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, although do not preclude the presence or addition ofone or more other features, integers, steps, operations, elements,components, and/or groups thereof.

The description of the present disclosure has been presented forpurposes of illustration and description, however it is not intended tobe exhaustive or limited to the disclosure in the form disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of thedisclosure. The embodiment was chosen and described in order to bestexplain the principles of the disclosure and the practical application,and to enable others of ordinary skill in the art to understand thedisclosure for various embodiments with various modifications as aresuited to the particular use contemplated.

What is claimed is:
 1. A computer-implemented method for dynamicallyadapting a workload to expose performance issues, comprising: using aprocessor device operably coupled with a memory, performing: A) prior toa test run: initializing a diagnosis policy comprising evaluationcriteria used to assess performance of a system under test, the systemcomprising a plurality of applications with associated transactions; andinitializing an adjustment policy comprising rules for dynamicallyadjusting the workload for an identified transaction at run-time duringthe test run, wherein dynamically adjusting the workload comprisesselectively re-tasking virtual users from a workload pool to stressfunctionality of the identified transaction; and B) parallel to the testrun, performing at pre-determined intervals during the test run:collecting monitoring data for a pre-determined period of time; applyingthe evaluation criteria from the diagnosis policy to the collectedmonitoring data to assess current system performance; based uponidentification of a current system performance issue after the applying,performing: identifying a transaction associated with the current systemperformance issue; matching the identified transaction associated withthe current system performance issue with the rules associated with theidentified transaction as set out in the adjustment policy; and applyingthe rules from the adjustment policy to the identified transaction,thereby selectively adjusting the workload by increasing the workload inreal-time for the identified transaction while decreasing the workloadfor other transactions not exhibiting a performance issue; and storingthe collected monitoring data.
 2. The computer-implemented method ofclaim 1 wherein increasing the workload comprises increasing a number ofvirtual users tasked with running the identified transaction.
 3. Thecomputer-implemented method of claim 1 wherein initializing thediagnosis policy comprises specifying an outside evaluation tool toassess the performance.
 4. The computer-implemented method of claim 1wherein initializing the diagnosis policy comprises submittingapplication-dependent evaluation criteria targeted to measuringapplication performance metrics of a specific application under test. 5.The computer-implemented method of claim 1 wherein initializing theadjustment policy comprises providing: an initial workload, a maximumworkload, and a delta workload indicating how many additional virtualusers to add to stress functionality of the identified transaction,without exceeding the maximum workload.
 6. The computer-implementedmethod of claim 5 wherein the delta workload specifies a percentageamount.
 7. The computer-implemented method of claim 5 further comprisingsetting a period of time before an increased workload reverts to itsinitialized state specified as the initial workload in the adjustmentpolicy.
 8. The computer-implemented method of claim 1 whereininitializing the diagnosis policy comprises providing a set ofapplication performance metrics and associated application performancethresholds, and identifying a test tool used to provide the set ofapplication performance metrics.
 9. The computer-implemented method ofclaim 8 wherein the set of application performance metrics comprise atleast one of: throughput, response time, and cpu utilization rate. 10.An information processing system for adaptive workload adjustment of asystem under test, the information processing system comprising: amemory; a processor device communicatively coupled to the memory, theprocessor device performing a method comprising: A) prior to a test run:initializing a diagnosis policy comprising evaluation criteria used toassess performance of the system under test, the system comprising aplurality of applications with associated transactions; and initializingan adjustment policy comprising rules for dynamically adjusting aworkload for an identified transaction at run-time during the test run,wherein dynamically adjusting the workload comprises selectivelyre-tasking virtual users from a workload pool to stress functionality ofthe identified transaction; and B) parallel to the test run, performingat pre-determined intervals during the test run: collecting monitoringdata for a pre-determined period of time; applying the evaluationcriteria from the diagnosis policy to the collected monitoring data toassess current system performance; based upon identification of acurrent system performance issue after the applying, performing:identifying a transaction associated with the current system performanceissue; matching the transaction associated with the current systemperformance issue with the rules associated with the identifiedtransaction as set out in the adjustment policy; and applying the rulesfrom the adjustment policy to the identified transaction, therebyselectively adjusting the workload by increasing the workload inreal-time for the identified transaction, while decreasing the workloadfor other transactions not exhibiting a performance issue; and storingthe collected monitoring data.
 11. The information processing system ofclaim 10 wherein the diagnosis policy specifies an outside evaluationtool to perform a diagnosis on the collected monitoring data.
 12. Theinformation processing system of claim 10 wherein initializing theadjustment policy comprises providing: an initial workload, a maximumworkload, and a delta workload indicating how many additional virtualusers to add to stress functionality of the identified transaction,without exceeding the maximum workload; and wherein the method furthercomprises setting a period of time before an adjusted workload revertsto its initialized state specified as the initial workload in theadjustment policy.
 13. The information processing system of claim 10wherein initializing the diagnosis policy comprises submittingapplication-dependent evaluation criteria targeted to measuringapplication performance metrics of a specific application under test andthe application performance metrics comprise at least one of:throughput, response time, and cpu utilization rate.
 14. A computerprogram product for adaptive workload adjustment, the computer programproduct comprising: a non-transitory computer readable storage mediumreadable by a processing circuit and storing instructions for executionby the processing circuit performing a method comprising: A) prior to atest run: initializing a diagnosis policy comprising evaluation criteriaused to assess performance of a system under test, the system comprisinga plurality of applications with associated transactions; andinitializing an adjustment policy comprising rules for dynamicallyadapting a test workload for an identified transaction at run-timeduring the test run, wherein dynamically adjusting the test workloadcomprises selectively re-tasking virtual users from a workload pool tostress functionality of the identified transaction; and B) parallel tothe test run, performing at pre-determined intervals during the testrun: collecting monitoring data for a pre-determined period of time;applying the evaluation criteria from the diagnosis policy to thecollected monitoring data to assess current system performance; basedupon identification of a current system performance issue after theapplying, performing: identifying a transaction associated with thecurrent system performance issue; matching the identified transactionassociated with the current system performance issue with the rulesassociated with the identified transaction as set out in the adjustmentpolicy; and applying the rules from the adjustment policy to theidentified transaction, thereby selectively adjusting the workload byincreasing the workload in real-time for the identified transaction,while decreasing the workload for another transaction not exhibiting aperformance issue; and storing the collected monitoring data.
 15. Thecomputer program product of claim 14 wherein increasing the workloadcomprises increasing a number of virtual users tasked with running theidentified transaction.
 16. The computer program product of claim 15further comprising using an outside evaluation tool specified in thediagnosis policy for performing a diagnosis on the collected monitoringdata.
 17. The computer program product of claim 14 further comprisingsetting a period of time before an increased workload reverts to itsinitialized state specified as an initial workload in the adjustmentpolicy.